I've only looked at the first game, but it does seem very interesting to analyze. The white group around H2 is near death as well and I think Leela's evaluation considered that group to be threatened. Once that is solidly alive, it does switch to the semeai on the right. I probably would not have tenuki'd on move 206, but it appears safe when I read out how to respond after move 211. Moves 218 and 220 are reasonable tesuji's when played in a semeai (even if wrong for that semeai). I think you're right that there's probably plenty of analysis to do on how leela went wrong in the game. It may even be that weaker bots read out how to kill the S6 stones on the right and instead of focusing on a liberties race with a one eyed group.
On Wed, 2009-04-22 at 18:27 -0700, terry mcintyre wrote: > I haven't got a ladder example at the moment, but here's an instance > where Leela does not realize it is in terrible trouble. > > > I ( with my 8 kyu AGA rating) know with certainty by move 223 (T5) > that Black has captured a large white group. A stronger player could > read this out sooner than I. This fight is too big to lose for either > side; nothing else on the board matters. ( anyone? how early is this > outcome pre-ordained? ) > > > Based on the results of its analysis mode, Leela does not recognize > the outcome of this semeai until the large white group in the bottom > right is down to two liberties. > > The problem is even more stark in example2 -- similar board, black has > foolishly played one of his own liberties for illustrative purposes. > It is black's play, black has three liberties, white has three. Black > must take away a liberty from white to win the capturing race, or make > two eyes at T8. Black has only four playable moves; any other choice > fails. > > > Leela proposes - even after several minutes of analysis and a million > nodes - that Black should tennuki at H14. That would snatch defeat > from the jaws of certain victory; White would dive into T8 and win the > race. > > > I started this thread with the contention that analysis mode can help > developers find problems, I hope this example explains why. My theory > is that if a program could reliably recognize the outcome of such > capturing races five or ten moves sooner, it could crush the likes of > me. :D > > Terry McIntyre <terrymcint...@yahoo.com> > > "Government is an association of men who do violence to the rest of > us." > - Leo Tolstoy > > > > > ______________________________________________________________________ > From: Michael Williams <michaelwilliam...@gmail.com> > To: computer-go <computer-go@computer-go.org> > Sent: Tuesday, April 21, 2009 1:57:54 PM > Subject: Re: [computer-go] Reply to Lukasz and Don + Roadmap 2020 > > Mention the program so that the author can either refute your claim or > fix the bug. > > > terry mcintyre wrote: > > Is it reasonable to expect pro players to use 6-dan programs as a > tool for analysis? The pro players are markedly better - at a rough > guess, a pro player could give a 6 dan amateur human or program a 3 > stone handicap. > > > > On the other end of the scale, beginning players and mid kyu players > could indeed make good use of an analysis mode by a program which is > better than themselves. > > > > Lastly, an analysis mode would be helpful to developers, methinks. > After winning a game, I like to back up a few moves and find out when > the program realized that it was behind. This often happens several > moves after the fatal blow has already been struck. I know the feeling > too well, when stronger players deftly skewer my group and I only > discover the problem five moves later. What do they know that I don't? > What do they know that the program doesn't? > > > > We have a saying, you learn the most from reviewing games which you > have lost. An analysis mode can help developers to discover when their > pride and joy first begins to miss the target. > > Lately, I have been playing quite a bit with a commercially > available program. An almost-ladder which has an extra liberty will > apparently be evaluated the same as a true ladder, and the program can > be tricked into trying to capture my ladder-like position. This sort > of predictable flaw might provide a clue to improve the next version. > > > > Terry McIntyre <terrymcint...@yahoo.com> > > > > "Government is an association of men who do violence to the rest of > us." > > - Leo Tolstoy > > > > > > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > computer-go mailing list > > computer-go@computer-go.org > > http://www.computer-go.org/mailman/listinfo/computer-go/ > > _______________________________________________ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > > > > _______________________________________________ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
